The present invention relates to the field of general maintenance.
Many industrial, commercial, and household applications require the breaking up of relatively large objects into smaller pieces. This reduction process is variously referred to as cutting, chipping, shredding, mulching, or grinding, depending in part on the size of the end product. Cutting and chipping are historically accomplished by chippers using relatively few chipper knives mounted directly onto a rotating disc and a bed knife. The chippers can produce pieces ranging up to about xc2xe to 1xc2xd inches in size.
One of the major issues with respect to the design of such devices is maintenance. Maintenance and adjustment of chipper and bed knives can be extremely cumbersome. In many chippers, a team of two men is required to change the chipper knives, by working through holes in the side of the chipper body. Long feeler gauges must be used to adjust the gap between the chipper knives and the bed knives.
Another issue is the design and maintenance of the feed rollers. Traditionally, dirt and trash are carried into the chipper with the in-feeding of the brush and wood. The dirt usually falls into the lower feed roller. If not cleaned out, the dirt will lock up the feed roller such that it cannot rotate. In addition, the chipper knives are mounted to the rotating disc, usually, using xc2xd inch size Allen bolts with flat head sockets and a nut. The holes for the Allen bolts are exposed to the feed material and are easily plugged with debris. The debris strips out the holes making it difficult to change the knives.
To access these various components and areas, some manufacturers of the disk-style machines often hinge the upper half or quarter of the chipper body to service the knives. Such machines include the Model 1230 Chipper manufactured by Vermeer and the Model 90 Brush Bandit manufactured by Bandit. The bed knife, however, remains difficult to adjust. Some other manufacturers such as Carlenburg for Mittsonmurrel Drum Machines and Gravely Disk Chippers facilitate the servicing of knives by hinging the feed hopper or sliding the upper feed roller vertically in a slide with weights or spring down pressure. In many of these systems, replacing the feed rollers requires one to crawl inside the machine and awkwardly perform the replacement. Morey, U.S. Pat. No. 5,005,620 discloses an upper feed roller pivoted from the chipper drum centerline (called the pivoted down stream). Houston, U.S. Pat. No. 4,390,132 discloses a trailing arm that is pivoted from a point above the feed path. A hydraulic cylinder and a compression spring force the engagement with the tree (feed stock). To reduce the frequency of required access, most manufacturers of chippers with lower feed rollers simply place an auxiliary frame or compartment that traps the dirt and debris.
The present invention is directed, in a first aspect, to a brush chipper in which access to frequently maintained areas of the chipper is facilitated. According to the one embodiment of the invention, the chipper comprises a chipper-knife assembly, a feed-roller assembly, and a sliding apparatus that permits a part or the whole feed-roller assembly to move away from the chipper-knife assembly. This sliding apparatus preferably includes at least one track and at least one friction-reducing apparatus such as a sliding roller or a bearing.
Another aspect of the invention is directed to a mounting for the chipper-knife assembly. In a preferred embodiment, the chipper-knife assembly comprises a knife with at least one threaded opening attached to a support. To attach the knife, a bolt passes through the support to thread into the knife. The bolt can include a head and a stem, and the support is positioned between the knife and the head of the bolt.